Daikin DPS Installation And Maintenance Manual

Also see for DPS: Installation and maintenance manual Installation and maintenance manual Installation manual Installation and maintenance manual

Contents

Daikin DPS Installation And Maintenance Manual Manual pdf 98 page image

Control TemperatureThe “Control Temperature” is defined as the unit temperatureinput used to make the heat/cool changeover decision Thisdetermines whether or not cooling or heating is enabledThe user may select Space Temperature, Return Temperature,Outdoor Air Temperature or None for DAT units Normallyeither the Return or Space Temperature is selected as thecontrol temperature Outdoor Air Temperature may be used asthe control temperature for DAT units, but not for Zone ControlunitsWhen the Control Temperature Source is set to None, the unitno longer “changes over” between heating and cooling in thenormal manner Instead it acts as if it is always in the “cooling”mode of operation controlling to the discharge air cooling setpoint In this case the unit operating state will vary betweenCooling, Fan Only and Min DAT (heating) in order to maintainthe discharge air cooling set point The unit will only enter theHeating operating state and control to the discharge heatingset point for morning warm up purposesThe Control Temperature Source automatically reverts fromReturn to Space if both of the following are true:• The Return Air Sensor is not present and reliable• A network or local Space Sensor is present and reliableThe Control Temperature Source automatically reverts fromSpace to Return if both of the following are true:• The space sensor is not reliable (a valid spacetemperature value is not provided via the network andthe space temperature sensor is either in alarm or notpresent)• The return air sensor is reliable (present and not in alarm)The Control Temperature Source automatically reverts fromeither Outdoor Air or Mixed Air to Return if the Control Typeis Zone (Not DAT) If the return air temperature is not reliable,the control temperature may then revert to space as describedaboveThe Control Temperature Source automatically reverts fromMixed Air to Outdoor Air if Unit Type is not SCUA Control Temperature Fault that shuts down the unit isinitiated if any of the following is true• The return air sensor is not present and reliable andReturn Air is selected as the control temperature and aspace sensor is not available• A network or local space sensor is not present andreliable and Space is selected as the control temperatureand a return temperature sensor is not available• The OAT Sensor is not present and reliable and OutdoorAir is selected as the control temperature• The mixed air temperature sensor is not presentor reliable and Mixed Air is selected as the controltemperatureOccupied Temperature Set Points(See page 41 for more information)When the Use Tstat set point parameter is set to No, theOccupied Cooling Set Point and the Occupied Heating SetPoint may be set through the keypad or via a network signalIn this case these set points are changed whenever thenetwork or keypad value changes When the Use Tstat setpoint parameter is set to Yes these set points can only beadjusted through the zone thermostat Heating and cooling setpoints must not overlap The Occupied Heating Set Point mustbe equal to or less than the Occupied Cooling Set Point If aconflict occurs from values entered via the keypad or network,the Occupied Heating Set Point is automatically adjusted downto eliminate the conflict. When the Occupied Cooling Set pointis changed by more than 0 5 degrees through the wall mountedsensor, the Occupied Heating Set Point is raised or loweredthe same amount so that the difference between the Coolingand Heating set points does not changeOAT LockoutOn heat pump units, compressor heating (primary heat) isdisabled whenever the outdoor air temperature is below theLow Outdoor Air Ambient Heating Lockout set point or abovethe High Outdoor Air Ambient Heating Lockout set pointWhenever the outdoor air temperature rises above the LowOutdoor Air Ambient Heating Lockout set point or falls belowthe High Outdoor Air Ambient Heating Lockout set pointby more than the Heating Lockout Differential, compressorheating operation is re-enabledSupplemental heating (secondary heat) is disabled wheneverthe outdoor air temperature is above the High Outdoor AirAmbient Supplemental Heating Lockout Set Point Wheneverthe outdoor air temperature falls below the High Outdoor AirAmbient Supplemental Heating Lockout Set Point by morethan the Heating Lockout Differential, supplemental heatingoperation is re-enabledCompressor cooling operation is disabled whenever theoutdoor air temperature falls below the Low Outdoor AirAmbient Cooling Lockout Set Point Whenever the outdoorair temperature rises above the Low Outdoor Air AmbientCooling Lockout Set Point by more than the Cooling LockoutDifferential, compressor cooling operation is re-enabledOn non-heat pump units, heating is disabled wheneverthe outdoor air temperature is above the High Outdoor AirAmbient Heating Lockout Set Point Whenever the outdoorair temperature falls below the High Outdoor Air AmbientHeating Lockout Set Point by more than the Heating LockoutDifferential, heating operation is re-enabledCompressor cooling operation is disabled whenever theoutdoor air temperature falls below the Low Outdoor AirAmbient Cooling Lockout Set Point Whenever the outdoorair temperature rises above the Low Outdoor Air AmbientCooling Lockout Set Point by more than the Cooling LockoutDifferential, compressor cooling operation is re-enabled.OM 1141-3 • MICROTECH UNIT CONTROLLER 98 wwwoperator ’s guIde